Numbers of round spermatids, primary spermatocytes, and Sertoli cells will be determined per gram testis parenchyma and daily sperm production per gram tissue will be computed in 300-400 coroners' cases from Olmsted County, Minnesota, autopsied in 1930-1959 who died suddenly in the absence of chronic disabling disease. These will be compared to an equal number of similar cases autopsied recently. Since usually only paraffin blocks are available during the earlier period whereas only wet tissue preserved in formalin is available in recent years, we propose first to conduct a pilot study, utilizing 100 coroners' cases in the 1950s and 1960s for which both tissue blocks and wet tissues are available. The pilot study will determine if cell counts differ in tissue blocks and wet tissues of the same men and by how much, and whether or not any observed difference increases with time in storage. The pilot study is underway and should be completed by spring 2002.